1. Field of the Invention
This invention relates to a recirculating processing oven heater for use in heating processing gas as it is recirculated from the heater to an associated oven and back to the heater in a cyclical manner.
2. Description of the Prior Art
Processing ovens such as paint ovens and ovens for meat processing systems require recirculating heaters that will heat processing gas without introducing any contaminative gas components such as unburned combustible gases in the form of unburned hydrocarbons or carbon monoxide, etc. In order to provide this heating of processing gas without introducing contaminants, prior art heaters of this type have utilized a burner and a heat exchanger so that there is no direct contact between the burning flame and the processing gas being heated. The heat exchanger provides isolation of the burner flame and the processing gas so that unburned fuel such as natural gas or oil does not become introduced into the processing gas. While heat exchangers of this type provide uncontaminated heating of processing gas, the maximum efficiency of the heat exchangers is on the order of 60% and much of the heat from the burner flame is thus wasted. Increasing scarcity of fuels and their consequent ever increasing cost have made this wasted heat a significant cost factor in operating a processing oven heater.